---
id: additional-exports
title: Additional Exports
sidebar_label: Additional Exports
---

## `injectBeforeRender()`

A shortcut to register a before render callback

```ts
@Component({
    /*...*/
})
export class SceneGraph {
    readonly sub = injectBeforeRender(() => {}, 0);
}
```

:::info

`injectBeforeRender()` automatically cleans up the before render but it returns the reference to the clean up function.
We can call this function anytime to clean up the before render

:::

## `is`

A collection of utility functions to assert object type

```ts
is.obj(a); // checks if a value is an object; not an Array nor a Function
is.ref(a); // checks if a value is ElementRef
is.object3D(a); // checks if a value is an instance of THREE.Object3D
// and more
```
